How much solid waste and sludge does a tonne of raw hide leave in a tannery?

The European tanning reference document gives about 450 to 730 kilograms (kg) of solid waste per tonne of raw hide, plus about 500 kg of effluent sludge at 40% dry matter. The 450 to 730 adds up from trimmings, fleshings, splits and shavings, dust and finishing trimmings, without the sludge.

The chart's rows, per tonne of raw hide

• Untanned: trimmings about 120 kg; fleshings about 70 to 350 kg.
• Tanned: splits, shavings and trimmings about 225 kg.
• Dyed or finished: dust about 2 kg; trimmings about 30 kg.
• Sludge from effluent treatment: about 500 kg, at about 40% dry matter.
• Total solid waste printed: about 450 to 730 kg.

Does it add up?

Low end: 120 + 70 + 225 + 2 + 30 = 447, which rounds to the printed 450. High end: 120 + 350 + 225 + 2 + 30 = 727, which rounds to 730. So the printed total leaves out the 500 kg of sludge. If you want waste including sludge, add the sludge yourself: about 950 to 1,230 kg per tonne of raw hide.

The document's summary text says "approximately 600 kg of solid waste" per tonne. That sits inside 450 to 730, so the two do not conflict.

Why the split matters for your records

Waste you send out is Scope 3 category 5, and the factor depends on where each stream goes: a landfill, an incinerator, a farm or an energy recovery plant. Keep weights per stream from your weighbridge or disposal slips, not one lump. My reading, not the document's: sludge sent to a common treatment operator may be counted from that operator's data, so ask the operator.

Wet or dry weight

The document gives the sludge at 40% dry matter. Say on your report whether a weight is wet or dry, because the same sludge weighs 2.5 times as much wet as dry (1 / 0.40).

Example: 60 tonnes of raw hide a month

• Solid waste without sludge: 60 x 450 = 27,000 kg to 60 x 730 = 43,800 kg
• Sludge at about 500 kg per tonne: 30,000 kg wet, which is 12,000 kg of dry matter at 40%
• Waste including sludge: 57,000 to 73,800 kg a month

The 60 tonnes is an example. Use disposal slips and weighbridge tickets for the real monthly weights.

What Senseible does here

Senseible reads fuel invoices and electricity bills into records by billing period. Waste weights are not part of that, so keep tonnes per stream per month in your own sheet.

• Common effluent plant: which scope?
• Energy from tannery fleshings and sludge
• Raw hide to leather yield

Sources: European Commission, Integrated Pollution Prevention and Control (IPPC) Reference Document on Best Available Techniques for the Tanning of Hides and Skins, February 2003 edition (filed by the publisher as superseded), GHG Protocol Corporate Value Chain (Scope 3) Standard

Last reviewed 2026-11-06. Figures are from the February 2003 edition of the European tanning reference document, which the publisher files as superseded; its energy and effluent tables rest on European tanneries and on older studies. Check the current edition and your own records before you quote a number to a buyer.